Field of the Invention
The present invention relates to a state change management system for a manufacturing cell, and in particular, relates to a state change management system for a manufacturing cell in a cell control system that manages a manufacturing cell composed of multiple manufacturing machines.
Description of the Related Art
In a manufacturing cell operating in a large factory, multiple, different kinds of manufacturing machines, such as machine tools, robots or PLCs, are installed. A cell control system obtains various kinds of device-based or product-based manufacturing information items from those multiple manufacturing machines constituting the manufacturing cell, and the obtained manufacturing information items are used for various management tasks required in manufacturing, such as process management, quality management and safety management.
An example of the cell control system according to a conventional art will be described using FIG. 9.
A cell control system 10 includes at least one cell controller 11 that manages a manufacturing cell. The cell controller 11 includes a manufacturing management part 12, a storage device 13 and a communication device 14. The manufacturing management part 12 receives device-based or product-based manufacturing information items from multiple manufacturing machines 21 installed in a manufacturing cell 20 via the communication device 14, sorts out the received process-based manufacturing information based on information related to processes stored in the storage device 13 in advance, or gives determination results, which are based on information related to safety standards stored in the storage device 13, to the received manufacturing information items, to organize thereof as cell-based manufacturing information, and stores the organized cell-based manufacturing information in the storage device 13. Further, the manufacturing management part 12 transmits the manufacturing information stored in the storage device 13 to a production planning device 30 via the communication device 14.
As a conventional art related to the cell control system, for example, in Japanese Patent Application Laid-Open No. 05-253813, with the aim of speedy communication of messages and prevention of leakage in message communication, a technique is disclosed in which a message is inputted from a cell controller to an initial screen of a numerical controller when power is turned on, to thereby cause the initial screen to display the message every time the power is turned on or in every break time.
Moreover, in Japanese Patent Application Laid-Open No. 10-320011, with the aim of making development of a cell control system and changes thereof with ease, and responding flexibly to change or addition of tasks, there is disclosed a technique including an execution control module that performs description and interpretation of procedures of tasks and a functional module that executes information processing or equipment operation necessary for the tasks, to thereby execute the tasks according to messages sent from the execution control module.
Further, in Japanese Patent Application Laid-Open No. 6-309011, with the aim of saving the effort of creating programs independently for respective appliances and providing an integrated program interface, a technique is disclosed in which operation software for a manufacturing cell is procedurally described in one programming language.
Multiple manufacturing machines installed in a factory are, in general, controlled by respective controllers produced by different manufacturers. Moreover, in some cases, even the manufacturing machines of the same type (for example, machine tools) in a manufacturing cell are controlled by controllers produced by different manufacturers, and in some other cases, further, even the controllers produced by the same manufacturer are of different models.
Therefore, in a manufacturing cell, various kinds of event information items, such as alarms, warnings or changes in machining conditions (for example, tool exchange or changes in main program selection) generated in a controller for controlling manufacturing machines, are displayed in different formats on indicators provided in the respective controllers, and are notified to the cell controller in many cases. Further, if manufacturing countries of the controllers are different, the various kinds of event information items are indicated and notified in different languages in some cases.
As described above, since the formats or languages of the various kinds of event information items, such as alarms, warnings and changes in machining conditions, collected by the cell control system are different by the respective manufacturing machines and are not standardized, it is inefficient to collect the event information items from the manufacturing machines, and then summarize and manage as cell-based information. Moreover, since handling of the collected information is complicated, when maintenance or change of the cell control system is needed, it takes time to address, and sometimes becomes difficult to easily accomplish maintenance or change.
Against such a problem, the technique described in the foregoing Japanese Patent Application Laid-Open No. 05-253813 transfers a common message to all of the numerical controllers connected to the cell controller to make the numerical controllers indicate the common message; however, the technique does not standardize the messages generated from the different numerical controllers and does not collect standardized messages on the cell controller side.
Moreover, in the technique described in the foregoing Japanese Patent Application Laid-Open No. 10-320011, the cell controller is able to flexibly respond to change or addition of tasks; however, the technique does not standardize messages generated from the different controllers to be collected on the cell controller side.
Further, the technique described in the foregoing Japanese Patent Application Laid-Open No. 6-309011 is configured to save the effort of creating programs independently corresponding to manufacturing machines controlled by controllers of different languages, such as the robot language, the ladder chart and the C language; however, the technique does not standardize messages generated from the different controllers to be collected on the cell controller side.